A grocer blends coffee beans from Columbia, Kona and Madagascar in the ratio $2:3:4$, respectively. In a $207$-kilogram blend, how many kilograms of Madagascar coffee beans are there?
Explanation: In any given blend, $\frac{4}{2+3+4} = \frac{4}{9}$ of the beans are Madagascar coffee beans. Therefore, in a 207-kilogram blend, there are $207 \times \frac{4}{9} = \boxed{92}$ kilograms of Madagascar coffee beans.